Infertility and spontaneous abortion - Spontaneous abortion, habitual abortion
Maternal age and fetal loss
Abstract
Objective: To estimate the association between maternal age and fetal
death (spontaneous abortion, ectopic pregnancy, stillbirth), taking into
account a woman's reproductive history.
Design: Prospective register linkage study.
Subjects: All women with a reproductive outcome (live birth, stillbirth,
spontaneous abortion leading to admission to hospital, induced abortion,
ectopic pregnancy, or hydatidiform mole) in Denmark from 1978 to 1992; a
total of 634 272 women and 1 221 546 pregnancy outcomes.
Main outcome measures: Age related risk of fetal loss, ectopic pregnancy,
and stillbirth, and age related risk of spontaneous abortion stratified
according to parity and previous spontaneous abortions.
Results: Overall, 13.5% of the pregnancies intended to be carried to term
ended with fetal loss. At age 42 years, more than half of such pregnancies
resulted in fetal loss. The risk of a spontaneous abortion was 8.9% in women
aged 20-24 years and 74.7% in those aged 45 years or more. High maternal
age was a significant risk factor for spontaneous abortion irrespective
of the number of previous miscarriages, parity, or calendar period. The
risk of an ectopic pregnancy and stillbirth also increased with increasing
maternal age.
Conclusions: Fetal loss is high in women in their late 30s or older, irrespective
of reproductive history. This should be taken into consideration in pregnancy
planning and counselling.
Pregnancy outcomes by maternal age at conception in 634 272 women in Denmark, 1978-92
| Maternal age | Live births |
Spontaneous abortions* |
Spontaneous abortions per live births |
Induced abortions |
Ectopic pregnancies |
Stillbirths |
All pregnancy outcomes |
| 12-19 | 44 674 | 5 427 | 12.1% | 49 884 | 808 | 223 | 101 016 |
| 20-24 | 246 038 | 24 465 | 9.9% | 74 683 | 4 163 | 1 046 | 350 395 |
| 25-29 | 312 904 | 33 728 | 10.8% | 59 014 | 7 233 | 1 270 | 414 149 |
| 30-34 | 157 457 | 22 391 | 14.2% | 48 641 | 5 861 | 699 | 235 049 |
| 35-39 | 43 471 | 11 369 | 26.2% | 36 195 | 2 679 | 226 | 93 940 |
| 40-44 | 5 101 | 3 962 | 77.7% | 15 421 | 614 | 34 | 25 132 |
| ≥ 45 | 117 | 509 | 435.0% | 1 184 | 54 | 1 | 1 865 |
| Total No of events | 809 762 | 101 851 | 12.6% | 285 022 | 21 412 | 3 499 | 1 221 546 |
| Total No of women | 509 867 | 85 838 | 16.8% | 223 426 | 18 968 | 3 457 | 634 272 |
*Includes 523 cases of hydatidiform mole.
Risk of fetal loss from spontaneous abortion, ectopic pregnancy, and stillbirth according to maternal age at conception
Risk of spontaneous abortion in nulliparous and parous women according to maternal age at conception and number of spontaneous abortions in preceding 10 years
